That just doesn't make sense. You can have an antonym for an adjective (the antonym of quick is slow), for an adverb (the antonym of quickly is slowly), and for certain verbs (sleep/wake, speak/shut up, etc.), certain abstract nouns (love/hate - also used as verbs) but it simply doesn't make sense to talk about antonyms of nouns which represent objects.
Muawiyah made the office of Caliph hereditary.
Caliph meaning the representative of God on earth
The territory of a Caliph is called a Caliphate.
The caliph,Uthman,organized the navy.
The Caliph's House was created in 2006.
The Muslim rulers after prophet Muhammad death in year 632 AD were called Caliphs. The first Caliph was Abou Bakr. The Caliph after death of the Caliph Abou Bakr was Omar Ibn Al-Khattab. That is why he was the second Caliph.
The first Caliph was Abu Bakr Assidik.
Caliph or Khalifa (خليفة) means "Successor"
The second caliph is Abu Jafar :)
The antonym of the word 'synonym' is 'antonym'.
A good caliph in the Muslim government needs to rule with authority.
Az-Zahir - Abbasid caliph - was born in 1176.